Geographic Range

Leaf deer (also known as leaf muntjacs), Muntiacus putaoensis, have been discovered in the Indo-Malayan ecozone and the Sino-Himalayan subregion of the Palearctic ecozone, which both extend across Asia. This geographic range is not surprising as it is consistent with the distribution of the entire Muntiacus genus, which is widespread in Asia. Specifically, leaf deer have been recently described in the Indian state of Arunachal Pradesh, which is rich in biodiversity. Leaf deer have also been previously described in northern Myanmar (Burma) and China. Leaf deer were identified in 1997, and due to this recent discovery, the extent of their geographic range is still being determined. (Amato, et al., 1999; Choudhury, 2009; Datta, et al., 2003; James, et al., 2008; Rabinowitz, et al., 1999)

Habitat

Leaf deer occupy the forests of isolated mountainous regions. They inhabit a wide array of forest types including tropical evergreen rainforests, sub-tropical hill forests and warm and cool temperate rainforests. Leaf deer have been observed at a range of elevations, from tropical evergreen forests at 800 m, to cool temperate rainforests at 3,000 m. Recently, leaf deer have been spotted in Arunachal Pradesh, which has 82% forest cover and high annual rainfall. There have also been reports of leaf deer inhabiting isolated mountains of both the Palearctic and Indo-Malayan ecozones. In China, leaf deer have been described along the western escarpment of the Yunnan Province and in mid-temperate areas with high floral densities. (Amato, et al., 1999; Arunachalam, et al., 2004; Choudhury, 2009; James, et al., 2008; Rabinowitz, et al., 1999)

Physical Description

Leaf deer are among the smallest known muntjacs. Their common name is derived from the practice of hunters wrapping their small bodies in a single Phrynium capitatum leaf. Their specific epithet is derived from the town they where they were first discovered, Putao, Myanmar. (Amato, et al., 1999; James, et al., 2008; Rabinowitz, et al., 1999)

Leaf deer are small cervids, commonly referred to as "fossil" deer, possessing "ancient deer" features. They currently represent the smallest known species of muntjacs, standing an average of 50 cm at the shoulder and weighing no more than 15 kg, with an average body weight of 12 kg (± 1.1 kg). They have an average head-body length of 80 cm (± 3 cm) and an average tail length of 10 cm (± 1.6 cm). (Amato, et al., 1999; James, et al., 2008; Rabinowitz, et al., 1999)

Leaf deer have small, rounded ears, with an average length of about 7.1 cm, which are more often than not, ripped and damaged. They have a patch of longer hair, forming a tuft in their forehead region. Generally, leaf deer are similar to common muntjacs, with reddish yellow pelage and a darkened anterior portion of their legs. They have dark facial markings that extend to the crown of their heads and have white ventral fur. Pelage coloration is variable, contingent on the particular individual, their age group, as well as the season of observation. Female leaf deer have been noted to be darker in early spring than early summer. This variation in pelage may be an adaptation to their woody environment and assist in avoiding predator detection. Leaf deer fawns are a rich chestnut color, but in contrast to common or Reeve's muntjacs, leaf deer fawns lack spots. As leaf deer fawns age, their pelage fades from a rich chestnut to the yellowish brown seen in adults. Leaf deer fawns reach adult height by the first year after birth, but may not reach adult weight for several years. (Amato, et al., 1999; James, et al., 2008; Rabinowitz, et al., 1999)

They show no sexual dimorphism in body size, but male and female leaf deer do differ in the presence or absence of antlers. Male leaf deer antlers are relatively short, ranging from 1 to 6 cm and, consistent with other muntjacs, are grown on large pedicels. Contrary to other muntjacs, leaf deer pedicels curve inward, causing the gap between the pointed, single-tine antlers to be small. Antlers are occasionally cast from deer that are at least 20 to 22 months old, but it is not a regular occurrence and is more commonly associated with older males. Most male cervids cast their antlers regularly and do not mate until after their antlers are hard again; however, muntjacs do not follow this pattern. (Amato, et al., 1999; James, et al., 2008; Rabinowitz, et al., 1999)

A feature of leaf deer that is not common to the entire genus is the presence of prominent frontal glands. Likewise, their skulls have large pre-orbital fossa. Another unique feature of leaf deer is the presence of tusks, formed from enlarged canines. These tusks have an average length of 2.4 cm and are often damaged or scraped. Their maximum skull length is about 20 cm, with an average of 17.5 cm (± 0.39 cm). They have an average nasal length of 4.7 cm (± 0.37 cm), an average nasal width of 1.6 cm (± 0.15 cm) and an average braincase width of 4.7 cm (± 0.3 cm). Their dental formula is (i 0/3, c 1/1, pm 3/3, m 3/3) X 2 = 34. (Amato, et al., 1999; James, et al., 2008; Nowak, 1999; Rabinowitz, et al., 1999)

Reproduction

Specific information on the mating systems of leaf deer has yet to be discovered.

Most male cervids cast their antlers regularly and do not mate again until their antlers are hard, which results in a regular birthing pattern, given that mating only occurs during certain months. Leaf deer do not exhibit a regular birthing pattern; rather, fawns are born during all months of the year. Although there are reports of higher reproductive outputs during certain times of the year, consistent with common muntjacs and Reeve's muntjacs, there is no defined reproduction pattern. In particular, pregnant and lactating females have been observed in early May, suggesting a higher breeding output in the late spring. (Barrette, 1977; Rabinowitz, et al., 1999)

The level of parental investment shown by leaf deer is unclear. However, reports of a sub-species of Indian muntjacs, Muntiacus muntjac malabaricus, indicate that female juveniles stay with their mothers longer than male juveniles. Fawns have been observed moving with their mothers, but usually spend their first two months immobile. (Barrette, 1977; Rabinowitz, et al., 1999)

Lifespan/Longevity

Information regarding the lifespan of the leaf deer is currently unknown.

Behavior

Leaf muntjacs are solitary. This is consistent with the notion that leaf deer represent an ancient group of deer. Ancestral deer were small, solitary, selective browsers of dense forests; more recent species are larger, more gregarious, grazers of open woodlands. Due to the size of their canines and their often damaged ears, it has been hypothesized that there are aggressive encounters among leaf deer. Interestingly, females also have enlarged canines and show ear damage. Although, female ear damage is less frequent, it is still notable and suggests female leaf deer are more aggressive than female muntjacs of other species. Indian muntjacs and Reeve's muntjacs show peaks of activity at dawn and dusk, but overall activity patterns suggest a diurnal habit. Given the similarity in habitat and feeding strategies, this activity pattern may apply to leaf muntjacs as well. (Barrette, 1977; James, et al., 2008; Linkie and Ridout, 2011)

Home Range

Further information regarding behavior has yet to be discovered; however, this species may be similar to other closely related muntjacs. A sub-species of Indian muntjacs are also reportedly solitary. These muntjacs are never observed in groups larger than four, and if observed in a group, it is most frequently a male female pair. Indian muntjacs are described as “strongly place bound”; restricted to a relatively small home range (4 to 5 km2). Leaf deer may be similar to Indian muntjacs with respect to home range size because leaf deer also occupy dense, complex forests. It is important for an animal to be able to maneuver their home range well, to be familiar with the land in a complex forest; the deer keep a home range that is relatively small. (Barrette, 1977; James, et al., 2008; Linkie and Ridout, 2011; Schaller and Rabinowitz, 2004)

Communication and Perception

Members of the genus Muntiacus are known as barking deer. Methods of communication specific to leaf deer are not currently known; however, the presence of traits across the rest of the genus imply leaf deer may also have similar characteristics. Indian muntjacs and Reeve's muntjacs produce sharp, dog-like barks. It is hypothesized that muntjac deer produce these calls in response to visual stimuli, such as predators, in the dense forests where visibility is restricted. This may serve as a warning to other nearby individuals or as a pronouncement of vigilance, a form of anti-predator behavior. (Barrette, 1977)

Food Habits

Given their similarity to a hypothetical ancient deer group, it is suspected that leaf deer are selective browsers of dense forests. Stomach content analyses have revealed that they are frugivores; the majority of their stomach contents consisted of partially digested fruits. Members of genus Muntiacus have been described as “nibblers”, preferring to eat fallen fruits. When they do browse, they are selective and only consume buds, flowers or the blades of leaves. Their morphology reflects their feeding habit; they have long tongues and wide lower incisors, both of which aid in collecting fallen fruit. This morphology can be contrasted to that of large grazers, who have large cutting incisors. Muntjacs move slowly while feeding, keeping their nose close to the ground and only moving a small distance. (Rabinowitz, et al., 1999)

Ecosystem Roles

There are no reports regarding the roles that leaf deer may play in an ecosystem. We can speculate, due to the knowledge of their diet, that leaf deer may hold an important role in dispersing seeds of fruit on which they feed. They digest the ovaries of the fruit and upon defecation; they may excrete the seeds in a variety of areas. (Rabinowitz, et al., 1999)

Ecosystem Impact

disperses seeds

Economic Importance for Humans: Positive

Leaf deer are relatively important economically for humans in the Indian and Asian areas. They are heavily exploited and are reportedly easy to capture with bear traps and are often shot by hunters. The meat of leaf deer is eaten and their skins are sold for leather. (Rabinowitz, et al., 1999)

Economic Importance for Humans: Negative

Conservation Status

The conservation status of leaf deer is listed as data deficient. As with many other facts about this recently discovered species, population information is difficult to collect due to their solitary lifestyle and habitat preference. Leaf deer ranges could be larger than what is currently known and as a result, conclusions regarding conservation status cannot be made.
Hunting of muntjacs in Arunachal Pradesh was prohibited by the Wildlife Protection Act in 1973, although documentation suggests hunting has persisted since then. In Myanmar, leaf deer occupy regions outside any protection areas. More observations need to be made to make further conclusions about leaf deer. They occupy isolated mountainous regions in areas that are relatively inaccessible, due to the rugged nature of the landscape as well as political instability. These factors have made travel for observations rather cumbersome and possibly dangerous. (Arunachalam, et al., 2004; Rabinowitz, et al., 1999; Timmins, et al., 2008)

Contributors

Glossary

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

diurnal

active during the day, 2. lasting for one day.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

sexual ornamentation

one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.

solitary

lives alone

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

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The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

This material is based upon work supported by the
National Science Foundation
Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.